Ansan Reed Wetland Park

Ansan Reed Wetland Park is Korea's first large constructed wetland, built so that reed beds could filter dirty water from the streams flowing into Sihwa Lake. Construction began in 1997 and finished in 2005, and today wooden boardwalks lead through the reeds past egrets, ducks and, with luck, water deer. Entry is free, and it makes an easy half-day walk.

A wetland built to save the "lake of death"

When the Sihwa sea wall closed off the bay between 1987 and 1994, the new lake filled with industrial and household waste water. Pollution soared far beyond the limit for farm irrigation, fish died in large numbers, and Sihwa became known as the "lake of death". As part of the clean-up, the Korea Water Resources Corporation built a wetland of about 1.03 million m² upstream, where the Banwolcheon, Donghwacheon and Samhwacheon streams enter the lake. The idea was simple: water flowing slowly through the reed beds cleans itself on the way.

The site was first called Sihwa Lake Reed Wetland Park. In 2014 management was split between Ansan and Hwaseong, and the Ansan side took its current name, while the Hwaseong side is known as Bibong Wetland Park.

What to see

• Environmental Ecology Center: A two-storey building with exhibits on the story of Sihwa Lake and how reeds remove pollutants. The upper floor looks out over the wetland.
• Observation trail: Wooden boardwalks and bird hides take you deep into the reed beds. The trail around the wetland is about 1.7 km long.
• Ecological pond and wildflower path: Irises, yellow flag and water lilies bloom around the pond where the filtered water finally collects.
• Wildlife: A 2014 survey recorded 111 bird species, including 11 designated natural monuments such as the mandarin duck and the common kestrel. Endangered species including the Eurasian otter, leopard cat, Seoul frog and boreal digging frog also live here.

How the wetland works

The wetland cost KRW 26.8 billion to build. As the first constructed wetland of its kind in Korea, it was designed with advice from an American engineering firm. Because the wetland lies higher than the surrounding streams, the water is pumped up into it. It then flows slowly through a series of shallow basins planted with reeds and other aquatic plants, growing cleaner at each stage, before passing through the ecological pond in front of the ecology centre and out into Sihwa Lake.

An artificial island in the middle gives wildlife a place to rest, and the deeper, reed-free water around it is a good feeding ground for birds. Ducks, black-crowned night herons, black-winged stilts, ruddy shelducks and great egrets come and go with the seasons, and Ansan has long been working to have the wetland listed as a Ramsar site.

Tripto tips

• Opening hours: 10:00–18:00 from March to October and 10:00–16:30 from November to February, closed on Mondays. Admission and parking are free.
• When to go: Autumn, when the reeds turn silvery, and winter, when migratory birds arrive, are the best seasons. The park has closed temporarily during bird flu outbreaks, so check before a winter visit.
• Time needed: Allow 1–2 hours for the ecology centre and the boardwalks.
• Getting there: Public transport is awkward. From the Sadong Juyuso bus stop it is about a 30-minute walk, so a car or taxi is easier. The address is 76 Galdaeseupji-ro, Sangnok-gu, Ansan.
• Bring: There is little shade, so take a hat and water. Nature programmes can be booked on the park's website.